constant is a number or a quoted character string (or other special notation) that indicates a fixed value. Constants are also called literals. query-expression is described in query-expression.

Read this SQL tutorial to learn when to use ... result set with three columns containing data from both queries. There’s no JOIN or condition to meet. By default, the UNION statement will ...

The EXISTS condition is an operator whose right operand ... in PROCLIB.PAYROLL is included in the output. Thus, the query returns all the employees from PROCLIB.PAYROLL who live in CT. proc sql; ...